Phytochemical Investigation of Origanum calcaratum Extracts and in vitro Study against Cellular Senescence

Origanum calcaratum is an endemic Greek species found in Cyclades, the Eastern Aegean Sea, and Northeastern Crete. The aim of this study was the thorough phytochemical analysis of O. calcaratum extracts and the in vitro assessment against cellular senescence. Overall, 27 constituents were identified in methanolic and hydromethanolic extracts by LC-MS and isolation techniques, predominantly phenolic compounds. Both extracts and rosmarinic acid showed noncytotoxicity to healthy cells. In Li-Fraumeni cells, they exhibited concentration-dependent senolytic activity, with rosmarinic acid and the hydromethanolic extract showing significant effects at low concentrations, while the methanolic extract was active only at higher concentrations. These findings highlight the selective senolytic potential of O. calcaratum, particularly the hydromethanolic extract and rosmarinic acid, supporting further investigation as antisenescence agents.